Here is a tip how you can convert a multiline text to single line(ie., how to remove newline characters) using regular expression.

Select "Use Regular Expression" in the find-n-replace dialog box. Enter "\n" in the "Find What:" field. Don't provide anything in the "Replace With:" and click the Replace or Replace All button. And voila.. All your contents are in a single lines now.

Here are more resources I found on the net on Find-n-Replace using regular expression: